This invention relates to an integrated horizontal and vertical seismic isolation bearing (ISIB). More specifically, an ISIB is a device which is installed between the ground and a superstructure and is utilized to block the energy of an earthquake being transferred from the ground to the superstructure. Seismic isolation bearings, which are installed between the ground and a superstructure, are devices effective to maintain the structural integrity of the superstructure by blocking the energy of an earthquake from being transferred from the ground to the superstructure. Conventionally used seismic isolation bearings are laminated elastic rubber-steel bearings which have a complex laminated structure or laminated rubber-steel bearings with embedded lead which can increase damping characteristics. These laminated elastic rubber-steel bearings are effective for only horizontal seismic isolation. Therefore, laminated elastic rubber-steel bearings, which are installed between the ground and a superstructure, provide excellent seismic isolation performance for a horizontal direction; however, seismic responses of a superstructure of large amplification can occur in a vertical direction due to the high vertical stiffness of such laminated elastic rubber-steel bearings.
Conventional laminated elastic rubber-steel seismic isolation bearings are used only for horizontal seismic isolation and have a high vertical stiffness to support the total weight of an isolated superstructure. It is difficult, therefore, for this horizontal seismic isolator with high vertical stiffness to provide vertical seismic isolation of body motion in a vertical direction of a rigid superstructure.